The Ebola virus has spread through Liberia, Guinea and Sierra Leone Getty

A clinical trial of an Ebola vaccine has been interrupted a week early after all the volunteers taking part reported pain in their hands and feet.

The trial, which was being carried out by Merck and NewLink, was halted "as a measure of precaution" after all 59 of the volunteers complained of joint pains in their hands and feet, the University of Geneva said in a statement.

"They are all fine and being monitored regularly by the medical team leading the study," the hospital said in a statement.

The trials are set to resume on 5 January in as many as 15 of the volunteers, pending checks that the symptoms were "benign and temporary", according to the hospital.

A number of companies have sought to fast-track a vaccine for the Ebola virus, which has spread through three countries in West Africa.

The trials would usually take 10 years to carry out, but health organisations are trying to complete the process in just 12 months.